Windows emulation software gives Linux desktop users the ability to run those "must-have" Windows programs. Computerworld community member Charles Bushong takes contenders VMware and Win4Lin for a test run -- and picks a winner.

Linux provides a very good upgrade path for servers in businesses of all sizes. Among the reasons for this are its versatility, ease of administration, minimal upfront cost and lack of client-access license entanglements. Also, users typically don't have direct contact with servers, so the underlying operating system isn't a big deal to them.
Not so with desktop computers for work or home.
My experience as a user and programmer on Windows operating systems -- and as a participant in some lively discussions that take place in the Computerworld community forums -- confirm that the transition to Linux isn't always easy for the user or the administrator. Almost all users have some Windows program that they must have in order for Linux to be as functional as Windows is for them.
Fortunately, there are a growing number of options for providing users with their must-have applications on a Linux desktop. I've discussed some of those in a previous story (see "Linux and Windows: Can't We All Just Get Along?"). This time, I've taken a hard look at two other alternatives.
Two Approaches, Five Programs
Emulation programs fall into roughly two groups: Those that require a Microsoft Windows license and those that don't. Programs that don't require a Windows license include the following:

Lindows, a $99 distribution of Linux that will run some Windows applications directly. It's due to ship soon from San Diego-based Lindows.com Inc.

VMware Workstation 3.0, $329 from VMware Inc. in Palo Alto, Calif. The company also offers a server version. (Regrettably, VMware Express, the $49.95 desktop version that I reviewed last time and runs one Windows 9x virtual machine at a time on Linux, has been discontinued.)

VMware vs. Win4Lin
Although the no-license options are getting better all the time, and new versions are about to be released, the products with the best compatibility with Windows applications still require a license for Microsoft Windows. Win4Lin and VMware Workstation aren't clones of each other, but they share certain qualities.
Both lack support for the DirectDraw and Direct3D Windows drivers that improve performance in graphical programs. That makes it impossible to play Windows games that are graphics-intensive. There are practical and technical reasons for this, not the least of which would be speed and incompatibility between these technologies and the graphical user interface Linux uses, called X Window System. If you want to play Windows games on your Linux machine, you'll either need to figure it out with Wine, which may work in some cases, or you'll have to dual-boot your machine.
That leads to the key difference between Win4Lin and VMware: the level of emulation. VMware is designed to create a complete virtual machine, and it performs very good hardware emulation. All devices are accessed through the underlying host operating system, and the file system may be a virtual drive that is contained in a file. It may directly access one or more standard File Allocation Table (FAT) 16 or FAT 32 partitions. However, all access to the Linux file systems is done through the Samba open-source file and print server software, which supports Windows clients. A "lite" version of Samba is included.
This is the clearest example of the VMware methodology. All access to the hardware is abstracted to the point where the guest Windows operating system layered on top of Linux can't distinguish between the real computer and the virtual machine. This is advantageous from a compatibility standpoint, but performance may suffer on slower computers.
Win4Lin takes an entirely different approach to emulation. It's more tightly integrated with the host operating system. For comparison, Win4Lin uses the Linux file system instead of creating a real or virtual FAT file system. It also makes certain parts of the install shared among all users of the machine. For this reason, there can be only one version of Windows installed on a Win4Lin machine. By contrast, VMware can have multiple Windows installations -- all different versions -- installed and running at the same time. However, Win4Lin files are directly accessible from Linux, even when the emulation isn't running. And it enjoys a performance boost from using the host operating system file services.
And the Winner Is ...
As with most things, the best choice depends on what you're trying to accomplish. If you need pretty good emulation on a slower computer, or if you just want better performance, Win4Lin is probably the way to go. If you need the best emulation you can get nad multiple version support, and if you can justify the substantially higher price, VMware may better meet your needs.
Overall, I liked both Win4Lin and VMware. They both include understandable installation instructions, although Win4Lin would be better for a newer user: It has a graphical installation program and offers better support for the most recent Linux kernels.
On the other hand, VMware comes with a few Linux distributions that include the VMware product as part of the install. You have the choice of installing VMware on the distribution of your choice or using their prepackaged distribution.
Ultimately, my wallet makes the decision for me. Win4Lin is $79.99 if you download it. VMware can be downloaded for $299, or $329 for the packaged distribution. Since the products compare so closely for my purposes, Win4Lin gets my business.
Bushong is a systems integrator and analyst in northeastern Ohio who uses Linux for everything from network infrastructure to servers to workstations. You can reach him at chuckb@systuff.com.Related stories
Read more of the Bushong Chronicles from the Computerworld Operating Systems Community pages:
Linux and Windows: Can't We All Just Get Along?Open source: Even beta is betterMicrosoft or Linux: De facto vs. Real Standards